The Evolution of Treatment for Hypothalamic Hamartoma
The prognosis for patients with hypothalamic hamartoma has improved dramatically over the last 20 years, for 3 main reasons. First, because of improved understanding of the anatomy and pathophysiology of these varied lesions. Second, due to advances in brain imaging and refinements in microsurgery, including the anterior transcallosal interforniceal approach, endoscopic, and skull-base approaches. And third, because of increasing experience with stereotactic radiosurgery, interstitial radiotherapy, and radiofrequency lesioning. Patients with hypothalamic hamartoma should be managed in comprehensive epilepsy centers where the treatments are individualized and concentrated in the hands of surgeons who can perform the full range of surgery, including approaches to the third ventricle. Total seizure-freedom rates of 52% to 66% have been achieved with surgery.
Hypothalamic hamartomas frequently cause intractable epilepsy with frequent gelastic and other mixed seizure types, intellectual disability, appalling behavioral disturbance with severe temper tantrums, and precocious puberty. Resection of the HH may cure the seizures and result in dramatic improvements in behavior, concentration, and the ability to learn new information. These children are given the chance to lead a relatively normal life and their parents are overjoyed to see this transformation in their child. A neurosurgeon could receive no greater reward.
Prior to the development of successful surgery for HH, the prognosis for these children was abysmal because the resulting epilepsy is particularly resistant to antiepileptic drugs and these patients frequently experience a relentlessly deteriorating clinical course. The seizures may occur every few minutes or even virtually continuously in those who are severely affected. This creates an epileptic encephalopathy that results in serious cognitive decline. Formerly, these children eventually became a complete burden on their parents, and family dynamics often became dysfunctional. Many of these children had a shortened lifespan and required institutional care. Successful intervention for these children has evolved, particularly in the last 20 years, and it is the purpose of this review to examine the factors responsible for this transformation. This paper reflects a personal view and does not attempt to exhaustively review and synthesize all the series of patients with HH reported in the literature, but instead attempts to focus on the principal developments in the field as observed from a personal perspective over this extended time period.
Mixed seizure patterns in patients with HH often electrically localize to the cortex. Because of this localization, frontal corticectomies and temporal lobectomies were performed without achieving control of the seizures. We identified examples of these patients in our series. The HH was not always noted on CT, particularly if it was small, and it was only after the introduction of MR imaging that the presence of the HH and its enormous anatomical variations were appreciated in these patients with intractable epilepsy. It is also challenging to diagnose gelastic seizures in infants. Some of these infants may be diagnosed with gastroesophageal reflux or colic. In some patients Lennox-Gastaut syndrome may be due to HH, but misdiagnosed.
Abstract and Introduction
Abstract
The prognosis for patients with hypothalamic hamartoma has improved dramatically over the last 20 years, for 3 main reasons. First, because of improved understanding of the anatomy and pathophysiology of these varied lesions. Second, due to advances in brain imaging and refinements in microsurgery, including the anterior transcallosal interforniceal approach, endoscopic, and skull-base approaches. And third, because of increasing experience with stereotactic radiosurgery, interstitial radiotherapy, and radiofrequency lesioning. Patients with hypothalamic hamartoma should be managed in comprehensive epilepsy centers where the treatments are individualized and concentrated in the hands of surgeons who can perform the full range of surgery, including approaches to the third ventricle. Total seizure-freedom rates of 52% to 66% have been achieved with surgery.
Introduction
Hypothalamic hamartomas frequently cause intractable epilepsy with frequent gelastic and other mixed seizure types, intellectual disability, appalling behavioral disturbance with severe temper tantrums, and precocious puberty. Resection of the HH may cure the seizures and result in dramatic improvements in behavior, concentration, and the ability to learn new information. These children are given the chance to lead a relatively normal life and their parents are overjoyed to see this transformation in their child. A neurosurgeon could receive no greater reward.
Prior to the development of successful surgery for HH, the prognosis for these children was abysmal because the resulting epilepsy is particularly resistant to antiepileptic drugs and these patients frequently experience a relentlessly deteriorating clinical course. The seizures may occur every few minutes or even virtually continuously in those who are severely affected. This creates an epileptic encephalopathy that results in serious cognitive decline. Formerly, these children eventually became a complete burden on their parents, and family dynamics often became dysfunctional. Many of these children had a shortened lifespan and required institutional care. Successful intervention for these children has evolved, particularly in the last 20 years, and it is the purpose of this review to examine the factors responsible for this transformation. This paper reflects a personal view and does not attempt to exhaustively review and synthesize all the series of patients with HH reported in the literature, but instead attempts to focus on the principal developments in the field as observed from a personal perspective over this extended time period.
Mixed seizure patterns in patients with HH often electrically localize to the cortex. Because of this localization, frontal corticectomies and temporal lobectomies were performed without achieving control of the seizures. We identified examples of these patients in our series. The HH was not always noted on CT, particularly if it was small, and it was only after the introduction of MR imaging that the presence of the HH and its enormous anatomical variations were appreciated in these patients with intractable epilepsy. It is also challenging to diagnose gelastic seizures in infants. Some of these infants may be diagnosed with gastroesophageal reflux or colic. In some patients Lennox-Gastaut syndrome may be due to HH, but misdiagnosed.